There is an increasing volume and sophistication of cyber attacks, particularly those aimed at web applications and servers, which deal in high-value traffic. Insecure applications and servers can lead to customer loss, financial loss, damaged reputation and legal conflicts. In an attempt to block cyber attacks from a group of hackers, for example, a company may identify the Internet protocol (IP) addresses associated with the hackers and block any attempt by the identified IP addresses to connect to the company's servers. However, IP addresses are not a reliable method to track the identity of an attacker. An attacker may use a proxy server, network address translation servers, or other mechanisms to hide and/or change the IP addresses from which the attacker is attacking the company.